1. Field of the Invention
The present invention relates to a continuous elongate ceramic article manufacturing system which manufactures ceramic articles through a series of continuous processes by continuously extruding a material containing clay as the principal component in a continuous, hollow or solid strip, drying the strip in a short time on the order of one to thirty minutes, cutting the dried strip into pieces of a fixed length, and firing the cut pieces to produce elongate ceramic articles.
2. Description of the Prior Art
As is well known, ceramic articles are manufactured through a series of an extruding process, a cutting process, a drying process, and a firing process. For example, tiles are manufactured through independent processes of extruding a material by an extruder in a continuous strip, cutting the strip in a fixed length, pressing the cut pieces in a fixed shape, drying the shaped pieces and firing the shaped and dried pieces, or pressing a material in a die in a fixed shape, drying the shaped pieces and firing the shaped and dried pieces.
However, the shaped pieces are plastic, it is very difficult to convey the shaped pieces without distorting the same. Elongate pieces, hollow pieces or thin pieces, in particular, are distorted easily, and hence it has been almost impossible to convey elongate pieces, hollow pieces and thin pieces continuously extruded by an extruder to the subsequent processes for drying and firing without distorting the same.
The drying process and the firing process, as well as the forming process, have difficulties in manufacturing ceramic articles. That is, first, drying and firing ceramic articles require a long time as long as several days to one week and, secondly, the shaped pieces deform greatly in the drying and firing processes. Hollow pieces, in particular, deform greatly as compared with solid pieces because the external surface is dried more rapidly than the internal surfaces defining the hollows when only the external surface is heated, and thereby the yield of the drying process is reduced.
Thus, the conventional ceramic article manufacturing system has drawbacks that the drying and firing process requires a long time of one to two days to prevent the shaped plastic pieces from twisting or cracking deteriorating the productivity of the manufacturing system and increasing the cost of the product. Furthermore, the conventional continuous ceramic article manufacturing system inevitably has a very long production arrangement because the drying and firing processes require a long time, hence such a very long production arrangement hardly is of a continuous ceramic article manufacturing system and it is impossible to dry and fire individual pieces separately because of the economy of cost and space. Accordingly, different from small clay pieces which are piled up with spacers therebetween for drying and firing, an elongate strip or plate is difficult to handle, and hence it has been impossible to manufacture a satisfactory elongate ceramic article at a reasonable cost due to problems resulting from the temperature difference between the central portion and the peripheral portion of the elongate strip or plate in the preheating zone, the firing zone and the cooling zone. Accordingly, it has never been thought of continuously drying elongate strips of one to three meters in length in a short time on the order of one to thirty minutes to constitute a ceramic article manufacturing system including the firing process in a short straight production line.